f"     7'elR(5uLAR"N'0.    141. 

United  States  Department  of  Agriculture, 


BUREAU   OF   EN 
L.  O.   HOWARD,  Entomolo 


thi:  mam; 

torhynchus 
Bj  C.  L.  M 

Thi  prospi  cti/Oi  mango  industry  of  /■  '< 
weevil  is  likely  to  b<  introduced  in  tin  seeds  of  thi  mango.  Shipments 
of  ma  igo  seeds  noxo  coming  to  this  country  an  largely  infested  with 
this  n'"  vil.  Introductions  of  any  mango  seed  or  fruit  into  mango- 
growing  districts  <>  ided  with  the  gravest  danger.  The  pre- 
■  '.cms  indicated  in  this  circular  should  be  strictly  carried  out. 

The  most  .serious  insect  pest  of  the  mango  in  oriental  countries  is  the 
mango  weevil  <  ( 'ryptorhynchus  mangifera  Fab.)  (fig.  1).     This  wee^  il 


Fig.  i  ryptorhynchus  mangiferx):  n.  Adult  weevil,  from  above;  b,  same,  from 

below.    Much  enlarged.    (Original.) 

is  related  to  the  boll  weevil  and  the  chestnut  weevil,  and  this,  aside  from 
its  well  know  n  de'st  ructive  \\  ork  on  the  mangoes,  is  sufficient  indication 
of  its  undesirability.  It  is  probably  of  Indian  or  at  least  of  oriental 
origin,  and  has  already  obtained  foothold  in  mosl  of  the  important 
mango-growing  countries,  being  carried  readily  with  seed  for  plant- 
ing. It  now  i  nl  ki  hits  all  of  the  mango  regions  bordering  on  the  Indian 
Ocean  and  adjacent  islands,  and  occurs  throughout  the  East  Indies, 

r.  141-11 


2  THE    MANGO    WEEVIL. 

including  the  Philippines  and  other  groups  of  South  Pacific  islands. 
It  has  gained  foothold  similarly  in  South  Africa  and  Madagascar  and 
numerous  other  points.  Fortunately  this  country  is  so  far  free  from 
this  pest,  and  if  it  can  be  kept  out  the  mango  industry  which  it  is 
hoped  to  develop  in  Florida  and  perhaps  in  the  other  warmer  parts  of 
this  country  can  be  given  a  very  great  advantage  over  other  mango- 
producing  regions  of  the  world.  The  insect  in  its  different  stages  is 
illustrated,  much  enlarged,  in  figures  1  and  2,  from  photographs  by 
Mr.  J.  G.  Sanders,  formerly  of  this  bureau. 

As  already  indicated,  this  mango  pest  belongs  to  the  weevil  family. 
The  egg  is  deposited  in  the  Meshy  part  of  the  fruit,  and  the  young 


^-^»-  . 

H  "If 

.  w 

Fig.  2.— The  mango  weevil:  a,  Larva;  b,  pupa.    Much  enlarged.    (Original.) 

grub  (fig.  2,  a)  burrows  at  once  into  the  seed  pod  and  develops  in  the 
seed  to  a  pupa  (fig.  2,  b)  and  finally  to  the  adult,  weevil,  or  beetle 
(fig.  1).  The  green  mango  soon  heals  up  over  the  egg  slit,  and  there 
is  very  little,  if  any,  exterior  indication  of  infestation.  The  weevil 
or  beetle  is  about  one-fourth  of  an  inch  long  and  dark  brown  in  color. 
It  remains  in  the  seed  for  some  time,  and  may  thus  be  easily  dis- 
tributed with  seed  for  planting  or  with  the  ripened  fruit. 

Protected  as  it  is  within  the  seed  pod  and,  in  fact,  within  the  seed 
itself  within  the  pod,  it  is  not  possible  to  destroy  it  by  fumigation  with 
any  certainty.     The  only  means  of  determining  infestation  is  in  open- 
ing the  seed  pod  and   removing  the  paper-like  covering  of  the  seed 
[Cir.  Hi.] 


THE    M  \N<.o    WEEVIL. 

itself,  when  normally  the  gnawing  and  excrement  and  discoloration 
due  to  the  work  of  the  larvae  and  weevil  can  be  noted.  Therefore  all 
seeds  introduced  for  planting  in  this  country  in  regions  where  mangoes 
are  grown  should  be  opened  in  this  manner  and  all  that  indicate  infesta- 
tion should  be  burned.  As  a  matterof  further  security  all  the  appar- 
ently sound  seeds  should  be  germinated  in  a  box  under  a  wire  screen, 
so  that  any  weevils  which  may  occur  iii  seeds  which  -how  no  visible 
Bign  of  infestation  ma\  be  retained  and  destroyed.  The  danger  is 
particularly  great  where  a-  is  now  the  case,  mango  seeds  are  being 
imported  for  planting  in  regions  in  Florida  where  fruiting  mango 
trees  occur.  Where  there  are  no  mango  tree-,  or  trees  of  fruiting 
age,  the  danger  is  perhaps  negligible,  as  no  other  food  plant  is  known 
for  the  mango  weevil.  Still,  if  large  numbers  of  these  weevils  should 
be  introduced  and  liberated,  they  are  lone-  lived  and  might  easily  be 
carried  on  railway  trains  to  regions  where  they  might  find  lodgment. 
It  is,  therefore,  desirable  in  any  case  to  observe  all  the  precautions 
indicated. 

It  has  already  been  stated  that  this  mango  weevil  is  the  principal 
enemy  of  the  mango  practically  wherever  this  fruit  is  grown.  In 
the  Hawaiian  Islands  Mr.  D.  L.  Van  Dine,  formerly  entomologist  of 
the  Hawaii  Agricultural  Experiment  Station,  reports  that  during  the 
first  year  of  bis  examination  he  found  t>0  per  cent  of  the  mangoes  in- 
fested and  the  following  year  from  80  to  90  per  cent,  in  some  instances 
a-  many  as  four  larvaa  being  found  in  a  single  seed.  While  the  mango 
weevil  destroys,  primarily,  the  seed  of  this  fruit,  it  is  also  believed  by 
grower-  to  hasten  the  maturity  of  infested  fruit  and  thus  increase  the 
percentage  of  fallen  mangoes. 

Inasmuch  as  this  insect  passes  it-  entire  development  within  the 
seed,  it  is  beyond  the  reach  of  insecticide-  and  fumigation,  and  tie 
only  remedy  which  the  bureau  i>  aide  to  advise  to  prevent  it  from 
becoming  a  pest  in  the  Tnited  State-  i-  to  collect  and  destroy  all  of 
the  fallen  or  supposedly  infested  mangoes. 

It  is  most  urgently  important  now.  however,  for  Florida  to  keep 
this  weevil  out.  Mango  seeds  are  now  probably  being  imported  into 
Florida  by  various  growers,  and  the  danger  of  such  importation  should 
be  thoroughly  understood,  and  whatever  authority  the  Mate  may  have 
to  prevent  or  control  such  importations  should  he  put  in  operation. 

Approved: 

.1  \mi-  Wilson, 

Sec/'  tary  of  Agricultun  . 

Washington,  1>.  ('..  May  !>,  1911. 

[Cir.  1411 

o 


UNIVERSITY  OF  FLORIDA 

ii  111  mi  mil  ii  mil1,  ii  ip.i  in 


3  1262  09216  5835 


